000
AXPZ20 KNHC 071605
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 07 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1545 UTC.

...ITCZ...

AXIS BEGINS AT 2N105W AND CONTINUES ALONG 5N117W 3N122W 4N140W.
SCATTERED MODERATE CONVECTION IS WITHIN 60-90 NM N OF THE AXIS BETWEEN
128W-134W...AND WITHIN 60 NM S OF THE AXIS BETWEEN 121W-123W.

...DISCUSSION...

W OF 130W...

BROAD MID/UPPER LEVEL RIDGING COVERS THIS PORTION OF THE DISCUSSION
AREA WITH THE PRESENCE OF A STRONG UPPER LEVEL JET STREAM BRANCH
WITH MAXIMUM WINDS OF 50-70 KT TRANSPORTING EXTENSIVE DEEP CENTRAL
TROPICAL PACIFIC MOISTURE NORTHEASTWARD INTO THE AREA FROM 6N TO 
22N. A MID LEVEL TROUGH EMBEDDED IN THE SW FLOW EXTENDS FROM 3N137W
TO JUST NW OF THE AREA NEAR 9N142W. SCATTERED STRONG CONVECTION 
IS WITHIN 90 NM EITHER SIDE OF THE TROUGH N OF 6N. THE UPPER 
FLOW BECOMES MORE W TO NW OVER THE NE PORTION IN RESPONSE TO A BROAD
UPPER TROUGH PUSHING S TO THE NE OF THIS AREA. AT THE SURFACE A STRONG
PRES GRADIENT BETWEEN SURFACE HIGH PRES AND LOWER PRES OVER THE TROPICS
IS RESULTING IN NE-E TRADES OF 20 KT TO THE N OF 6N AND W OF 
122W. SEAS OF 9-13 FT IN NW SWELL ARE OBSERVED N OF 14N. BY 48 
HOURS THIS AREA OF TRADES WILL SHORING SOME AS THE CULPRIT HIGH 
PRES TO THE NW OF THE REGION SHIFTS SW AND WEAKEN.

E OF 130W...

BROAD UPPER TROUGH EXTENDING FROM THE PACIFIC NW TERRITORY SW TO 
JUST NW OF THIS AREA IS ALLOWING FOR UPPER LEVEL SW TO W FLOW
TO DOMINATE OVER THE PORTION OF THE AREA N OF ABOUT 20N. THE EASTERN
PERIPHERY OF THE RIDGE DESCRIBED ABOVE W OF 130W EXTENDS INTO THE
WESTERN PORTION OF THIS AREA. OVER THE EASTERN PORTION...A MID/UPPER
LEVEL TROUGH IS ALONG 26N121W 16N112W 10N108W. WATER VAPOR IMAGERY
SHOWS MODERATE SUBSIDENCE RESULTING IN DRY STABLE AIR N OF 21N
AND E OF 118W. MODERATE SUBSIDENCE IS ALSO ALONG AND E OF THE 
TROUGH. AN E TO W UPPER LEVEL RIDGE EXTENDS FROM AND ANTICYCLONE
CIRCULATION OVER VENEZUELA TO 10N100W. MIDDLE TO UPPER LEVEL 
MOISTURE FROM PREVIOUS CONVECTIVE ACTIVITY OVER S AMERICA IS S 
OF THE RIDGE E OF 95W.

A SURFACE TROUGH IS ALONG 9N114W TO 4N120W. BROAS LOW PRES COVERS
THIS AREA.

PAPAGAYP NE TO E WINDS OF 20-25 KT ARE EXPECTED TO DIMINISH IN 
ABOUT 12 HOURS...THEN START UP AGAIN IN 48 HOURS AS NE 20 KT
WINDS WITHIN 30 NM OF LINE 11N86W TO 11N89W.

$$
AGUIRRE